A group of Neolithic burial monuments in southwest Britain around the Bristol Channel - megalithic tombs consisting of a long mound, tapering on one end, with one or more passage graves. In the finest tombs, the funerary area is a long gallery with up to three pairs of side chambers opening from it. In others, the courtyard leads only to a false entrance while the burial chambers open laterally onto the side of the mound. The Severn-Cotswold tombs were built early in the Neolithic period, and there is a radiocarbon date of 3600 +/- 130 BC from Waylands Smithy, Berkshire. The West Kennet tomb (3330 +/- 150) was constructed at much the same time as the nearby causewayed camp at Windmill Hill. In plan, these graves show a general similarity to the French transepted gallery graves around the mouth of the River Loire. There are two main varieties: axial-chambered tombs, with the passage entrance opening from the center of the broader end of the mound, and lateral-chambered tombs, where two megalithic chambers are entered from opposite sides of the mound.